The inverter is the heart of the photovoltaic power generation system. Solar microinverter not only plays an important role in converting the direct current generated by solar photovoltaics into alternating current, but also integrate electrical energy into the grid or use it in household appliances after completing the maximum power point tracking.
As the interface between distributed power source and grid, inverter performance will directly affect the power generation efficiency and operating stability of photovoltaic power generation systems.
1. What is a solar microinverter
Solar microinverter is an electronic device used in solar power generation systems, mainly used to convert direct current (DC) electrical energy generated by photovoltaic panels (solar panels) into alternating current (AC) electrical energy for home or commercial grid use.
Compared to traditional centralized inverters, solar microinverter is usually modular. Each PV panel with solar battery is equipped with a microinverter, so each PV panel can work independently. This design has some advantages, such as better reliability, higher energy yield, and a more streamlined installation.
2. How a solar microinverter works and its component
Solar microinverter works as follows:
● DC input
DC power generated by the photovoltaic panels is transmitted to the microinverter via a cable.
● Maximum power point tracking (MPPT)
Solar microinverter typically contains a maximum power point relay. It works by monitoring the output voltage and current of the PV panels to ensure that the maximum possible power is extracted from the PV panels.
Solar microinverter converts DC electrical energy into AC energy. In this process, it needs to adjust the output voltage and frequency to match the standard voltage and frequency of the home or commercial grid.
● Synchronization and grid connection
Solar microinverter must ensure that the AC power generated is synchronized with the grid and automatically stops working to ensure safety when grid voltage is unstable or power is cut off.
Solar microinverter typically consists of the following components:
- DC input
Used to connect the DC output of the photovoltaic panel to the microinverter.
- MPPT component
Used to track the maximum power point of the PV panel, ensuring that the maximum possible energy is extracted from the PV panel.
- Inverter circuit
A critical circuit in which DC energy is converted into AC power.
- Control circuits
Monitor and control the operation of microinverters, including synchronization and secure connection to the grid. The output connects the generated alternating current energy to the home or commercial grid. Since each photovoltaic panel is equipped with a microinverter, the efficiency of the entire photovoltaic power generation system will be higher, and once a photovoltaic panel fails, it will not affect the operation of the entire system.
3. Concentrated advantages of solar microinverter
● Broad market space
With the increase in the penetration rate of household photovoltaic and the establishment of DC side safety standards for power stations, solar microinverter with safer and more efficient characteristics are expected to be more widely used.
● Increasing multiple penetration rate
With the increase of the penetration rate of solar energy in the global energy structure, the penetration rate of distributed photovoltaics in photovoltaic installations and the increase of the penetration rate of household photovoltaics in distributed photovoltaic installations.
● Large alternative space
The market pattern for solar microinverter is relatively concentrated. After years of efforts, the top 10 photovoltaic battery companies in the world have gradually caught up in technical strength and product iteration speed, and are rapidly developing the market through cost-effective differentiated competition strategies.
● Greater security
In principle, the centralized or serial inverter first connects multiple components in series and then performs the inverter, and the DC voltage connected to each string component is high, and there is a certain risk of electric shock.
In addition, in the case of high DC voltage in the photovoltaic string, once the joint is loose, the contact is poor, the wire is damaged, etc., resulting in a huge fire hazard. In contrast, microinverters convert the direct current generated by each component into alternating current and then connect it in parallel, which has a higher safety factor.
● Higher power generation efficiency
Under certain temperature and light conditions, the output voltage and current of photovoltaic modules follow a specific curve. At the same time, the curve changes with light and temperature. Therefore, under different external conditions, the voltage and current corresponding to the maximum power point of the photovoltaic module are usually different.
In addition to DC/AC conversion, another core role of solar microinverter is to continuously adjust circuit parameters so that photovoltaic modules are always output at their maximum power point, that is, maximum power point tracking (MPPT). For centralized or string inverters, because each string of components is output at the same current.
If a component fails or the output power drops due to faults, occlusions, shadows, etc., the power generation efficiency of the entire string of modules will be affected. For pv systems using solar microinverter, each module corresponds to an independent MPPT, which can ensure that each module is output at its own maximum power point. So the overall power generation efficiency of the system will not be affected by the "short board" and appear to decline significantly.
● More flexible installation
Generally, the weight of the solar microinverter is only about 1-3 kg (single/double model), while the weight of the household string inverter is generally more than 10 kg, so whether it is in transportation, storage or installation, the microinverter has better convenience.
● Better monitoring and management
From the perspective of photovoltaic system operation and maintenance, solar microinverter can reduce the maintenance cost of the whole life cycle.
4. Solar microinverter applications and residential photovoltaic systems
The home energy storage refers to the installation of photovoltaic modules on the top floor or courtyard of family homes, the use of module-level inverters for the converter process, and the direct use of new energy. They can also integrate excess electricity into the grid.
The electricity load of a single household is generally small. As long as a family has a small site, such as a balcony or roof, a household photovoltaic system can be installed, and the electricity generated by a small household photovoltaic system is enough for a family to use and have surplus.
● Limitations of household pv system
- Security issues
If the safety performance of the photovoltaic system is not good, there is a risk of fire, which not only brings property damage, but also directly affects the return on investment.
- Difficult to operate and maintain
Without intuitive component-level data, inspections become more difficult, making it difficult to locate faults and find their causes.
- Power generation efficiency
Trees around the house, water heaters on the roof, etc. will cause shadow obscuration, affecting the efficiency of power generation. In view of the above reasons, household PV needs more safe PV products, intelligent operation and maintenance and high power generation efficiency.
Potential solar microinverter features module-level monitoring. Not only is it safe and efficient, but also paired with the intelligent cloud monitoring platform, the working status of each component can be monitored in real time.
● Advantages of solar microinverter over residential use
- Small and lightweight, easy to install and maintain.
- High efficiency can increase the power generation of solar power generation systems.
- Low noise and does not affect home and commercial use.
- Safe and reliable, with perfect protection function.
- Save money on your electricity bills and reduce your environmental impact.
Microinverters are ideal for solar power systems. The coordinated operation of the inverter with components such as the battery allows the solar power system to efficiently convert solar energy into alternating current energy that can be used for commercial consumption. Inverters play an important role in solar power systems. They convert direct current generated by solar panels into alternating current, making it usable in homes and businesses.
5. ConclusionSolar microinverter has a large market space in the future and have obvious advantages over existing centralized and serial inverters. At the same time, solar microinverters are still in the low penetration stage, and the industry has great investment potential.